To analyze the imaging features of the proximal fibula osteosarcoma and summarize its imaging diagnosis characters and differential diagnosis in this region.

Retrospectively analyzed the X-ray, CT and MRI of 6 cases of proximal humerus osteosarcoma were confirmed by pathology from January 2004 to December 2016, and analyzed the imaging findings, including the shape of the tumor, the destruction of the bone, and the bone of density in the lesion, density, periosteal reaction and range of encroachment.

There were 4 males and 2 females, aged from 50-72 years old. There were 2 cases of osteolytic type, 3 cases of mixed type, and 1 osteogenic type. Two osteosarcoma occurred at epiphysis and 4 occurred at metaphysis. Only 2 of 6 patients had periosteal reaction, of which 1 was Codman's triangle and 1 was parallel periosteal reaction. No periosteal reaction was found in bone-end osteosarcoma. MRI, T1WI showed moderate and low mixed signals, T2WI showed high and low mixed signals, and 6 patients had soft tissue lumps.

The mixed type was more common in osteosarcoma in the proximal end of fibula. The radial periosteum reaction and Codman triangle were rare, especially osteosarcoma located at the bone end. Osteolytic osteosarcoma without periosteal reaction should be distinguished from benign tumors such as giant cell tumors and chondroblastomas that occur at the ends of the fibula.